Trench Excavation Shoring for Residential Application

[asixth]

Hi guys

I am providing the design work for a residential renovation work where I need to excavate a 4' by 8' trench 9' deep. I am only 4' from the property boundary.

My first thought was to use a prefabricated propriety trench box but because of site limitations it was requested to shore the excavation as we dig.

Has anyone got a methodology on how to do this type of work?

The idea's that have been presented in the office is to drive hardwood sleepers down the excavation and provide a steel ring to brace the excavation.

Does anyone have some good detailing and construction methodology for this type of structure?

I have provided a sketch of the existing structure and a typical trench box that I am trying to achieve.

Regards

 

[bridgebuster]

You should probably be able to use timber - sheeting, walers, and struts - assuming your basement wall can take the loads. This is commonly done by utility companies in NYC on active streets.

If you're looking for references, try Caltrans Trenching and Shoring Manual, FHWA RD 75-128, CFR 1926 Subpart P. The last one has tables for timber shoring.